Brush



C. JOBST Dec. 10, 194-0.

BRUSH Filed Aug. 16; 1937 FIGJ.

FIGZ.

ATTORNEYS Patented Dec. .10, 1940 I BRUSH Conrad Jobst, Toledo, Ohio, assignor, by memo assignments, to The Owens Staple-Tied Brush Company, Toledo, Ohio, a corporation of Ohio Application August 16, 1937, Serial No. 159,419

4 Claims. (cars-167).

further object to obtain this result even where the tuft is formed of relatively fine, or what is commonly known as soft bristles. With these and other objects in view, the invention consists in the construction as hereinafter set forth.

In the drawing:

Figure 1 is a side elevation of my improved brush as designed for a tooth brush;

Figure 2 is a plan view of the brush back or handle showing the arrangement of the tuft receiving bores therein;

Figure 3 is an enlarged sectional plan view of the brush on line 3 -3 of Figure 4;

Figure 4 is an enlarged longitudinal section of Figure 3 partly in elevation;

Figure 5 is an enlarged cross section 5-5 of Figure 3.

In the manufacture of tooth brushes and other brushes of a similar character it is customary to secure the tufts to the brush back or handle by setting the same in spaced bores. This spacing of the tufts is desirable for sanitary reasons, but in use the outer bristles of each tuft are subjected to more severe stresses than the inner bristles. As a consequence, there is a tendency for these outer bristles to break off and in time to destroy the brush. I changed even where the size of the bundle of bristles formin' the tuftis enlarged, for after the outermost bristles have been broken, those next adjacent will break in a similar manner and so on until the whole tuft is destroyed.

To overcome the defect just described I have designed a construction in tufts are set so close to each other as to form a mutual reinforcement and to constitute in efiect a single tuft. This composite tuft is then trimmed so that only the central bristles come into direct contact with the work, the outer bristles being too short for engagement and constituting a resilient reinforcement for the inner bristles. Thus, a much higher degree of rigidity is imon line parted to the tuft even where composed offine or soft bristles, and the length of life is also greatly increased. Furthermore, the construction is one which is sanitary for each composite tuft may be suitably spaced from an adjacent composite tuft.

the enlarged views 3, l and 5, the

As shown in brush back or handle A is provided with transwhich a plurality of each group having a C bear against each versely extending double rows of bores B which are very close to each other and as a group form in effect an oblong substantially rectangular flgure.- The diameter of each bore is preferably considerably less than usual for receiving inde- 5 pendent tufts, such for instance as .049 of an inch. Each bore has set therein a tuft C of cor- I responding size, preferably secured by an anchor D. The adjacent bores are so close that the tufts other a short-distance above the back and form in effect a single tuft. This is subsequently trimmed to taper each of the sides toward the top, as indicated at E, F, G and H, and thus only the central bristles come in contact with the work, and these are supported and reinforced by the shorter outer bristles. In fact, the construction'is quite similar to that of a leaf spring in which onlythe long leaves directly support the load, but-are indirectly supported by the shorter leaves;

In the specific construction illustrated in Figure 1 which is designed for a tooth brush, a series. or group of multiple tufts I are constructed as illustrated in Figures 3, 4 and 5, and are spaced from each other longitudinally of the handle, as shown. The end multiple tuft J has, in addition to the two rows, a third short row C which is obliquely trimmed and forms an additional reinforcement for the central bristles in a direction longitudinally of the brush. Thus in use, this end tuft which is subjected to greater longitudinal stresses than the others, is strengthened and stiffened for this purpose.

What I claim as my invention is:

1. a tooth brush comprising a handled back 85 provided with spaced groups of parallel bores, plurality of rows of bores extending transversely of the back, said rows and the adjacent bores in each row being in close proximity to each other, and individual tufts set in the bores of each group, the outer portions thereof merging a short distance from the back to form in effect a single tuft for each group, the

latter being trimmed transversely and longitudinally to press only the central bristles of the 4 group to the work-the outer bristles on all sides thereof being shorter and forming a resilient reinforcement for said central bristles.

2. A tooth brush comprising a handled back provided with spaced groups of parallel bores, each group having a plurality of rows of bores extending transversely of the back, said rows and the adjacent bores in each row being in close proximity to each other, and individual tufts set in the bores of each group, the outer portions thereof merging a short distance from the back to form in effect a single tuft for each group, the latter being trimmed transversely and longitudinally to press only the central bristles of the group, to the work, the outer bristles on all sides thereof being shorter and forming a resilient reinforcement for said central bristles, the end group being-provided with an extra trimmed row of tufts forming an additional reinforcement against longitudinal stresses.

3. A tooth brush comprising a handled back provided with spaced groups of parallel bores each group having a plurality of rows of bores extending transversely of the back, said bores being of relatively small diameter and so closely spaced that adjacent bores are substantially tangent to each other, and individual tufts set in the bores of each group the bristles thereof having relatively slight angular divergence but merging with those of adjacent tufts a short distancejfrom the back to form in efiect a single tuft for each group the latter being trimmed obliquely to form longer bristles resiliently reinforced by bristles which are progressively shorter toward an outer side of the tuft and the distance between the bores of one group and the adjacent bores of another group being suflicient to space the tufts in the respective groups from each. other.

4. A tooth brush comprising a handled back provided with spaced groups of parallel bores each group having a plurality of rows of bores extending transversely of the back, said bores being of a diameter of the order of .050 of an inch and being spaced from each other by less 7 than .015 of an inch and individual tufts set in the bores of each group the outer portions thereof merging a short distance from the back to form in eflect a single tuft for each group, the latter being trimmed obliquely to form long bristles resiliently reinforced by bristles which are progressively shorter bristles toward an outer side of the tuft.

CONRAD J OBST. 

